Could the Climate Rule Come Undone?

Earlier this month, the White House rolled out draft regulations to limit carbon emissions from the nation's fleet of existing power plants.

The rules aren't expected to be made final for at least another year, and the administration is rushing to finish the regulations before President Obama leaves office. But attacks on the rules have already begun. Republicans in the House and Senate are hoping to add ammendments to must-pass spending bills that would block the rules.

There are other threats as well. They're sure to face a litany of legal challenges. And last week, I wrote about the possibility that future administrations could undermine, weaken, or even roll back the regulations (Read the story here).

What are the immediate and long-term threats to the climate rule? And what makes the regulations vulnerable? What can be done to either unravel or protect the regulatory regime that the Obama administration has worked to put in place?